Anti-Quorum Sensing and Anti Biofilm Compounds from Marine Microbiome

Quorum Sensing (QS) is a cell to cell communication process relying on the production of signaling molecules that enable the synchronization of gene expression. This process affects different microbial community functions including the ability to develop biofilms. Understanding these communication processes can help develop novel methodologies for producing antimicrobials agents. To date, less than 1% of microbes can be isolated using traditional culturing techniques. Despite this, the emergence of culture-independent and metagenomic techniques allows access to information regarding biochemical pathways characterizing these uncultured microorganisms. In order to assess the quorum sensing inhibition characteristics of uncultured bacterial species, 2500 environmental Bacterial Artificial Chromosome (BAC) vectors from a Red Sea metagenomic library were screened using soft agar overlay with two indicators bacteria C. violaceum and A. tumefaciens KYC55. Theses screening methods suggests that QSI ability is common in the marine environment. The results indicated that the most active compound (14-A5) found in this study, possess not only the ability to disrupt QS signaling pathways, but also are able to reduces biofilm formation of P. aeruginosa and A. baumannii. The active synthesized compound (MetProDKP) has anti- biofilm properties against P. aeruginosa PAO1 strain (the total surface bio-volume dropped up to 97.2%). In order to fully unravel, the mechanism of the reported inhibition activity, additional research endeavors are still required. This study validates that present functional screening technique for QSI metabolic activities enables us to further advance our understanding about the abundance of QSI molecules in the marine environment.